New Trigeminal Stimulation Technique with Dorsal Root Ganglion Stimulation Electrode and Maxillary Fixation: Technique Description.

BACKGROUND: Trigeminal neuralgia is considered the worst pain a human being can experience. Initial treatment uses anticonvulsant sodium channel blockers, which relieve pain in approximately 70% of patients. In refractory cases, it is possible to perform ablative treatments, decompressive surgeries, and neuromodulatory techniques. METHODS: This report describes the treatment of a patient with refractory trigeminal neuralgia who continued to have a painful clinical presentation after four surgical procedures and three ablative procedures. The patient presented with severe pain (verbal numerical scale between 9 and 10), manifesting an evident suicidal ideation. A dorsal root ganglion (DRG) stimulation electrode was implanted in the trigeminal ganglion through intraoral puncture with maxillary fixation of the electrode, in order to minimize the chances of displacement. The test phase consisted of implanting a quadripolar electrode for DRG stimulation through puncture lateral to the buccal rim in a fluoroscopic coaxial view. The electrode was fixed to the skin and maintained for 5 days, during which the patient remained completely pain free. After the 5-day test period, the definitive stimulation electrode was implanted, this time with intraoral puncture and maxillary electrode fixation. RESULTS: The patient remains pain free in the 3-month follow-up, with no displacement of the electrode. CONCLUSIONS: The DRG electrode may be considered a therapeutic option in patients with severe trigeminal neuralgia. Controlled studies must be performed to determine the efficacy and safety of the method.

Off-label use of rhBMP-2 as bone regeneration strategies in mandibular ameloblastoma unicystic / Utilização off-label das rhBMP-2 como estratégia de regeneração do tecido ósseo em ameloblastoma mandibular

ABSTRACT Jawbone reconstruction after tumor resection is one of the most challenging clinical tasks for maxillofacial surgeons. Osteogenic, osteoinductive, osteoconductive and non-antigenic properties of autogenous bone place this bone as the gold standard for solving problems of bone availability. However, the need for a second surgical site to harvest the bone graft increases significantly both the cost and the morbidity associated with the reconstructive procedures. Bone grafting gained an important tool with the discovery of bone morphogenetic proteins in 1960. Benefit of obtaining functional and real bone matrix without need of second surgical site seems to be the great advantage of use bone morphogenetic proteins. This study analyzed the use of rhBMP-2 in unicystic ameloblastoma of the mandible, detailing its structure, mechanisms of cell signaling and biological efficacy, in addition to present possible advantages and disadvantages of clinical use of rhBMP-2 as bone regeneration strategy.

RESUMO A reconstrução óssea dos maxilares após ressecções tumorais é uma das tarefas mais difíceis para o cirurgião maxilofacial. As propriedades osteogênicas, osteoindutoras, osteocondutoras e não antigênicas do osso autógeno o colocam como o padrão-ouro para a solução de problemas de disponibilidade óssea. Entretanto a coleta do enxerto ósseo necessita de um segundo sítio cirúrgico, aumentando significativamente o custo e a morbidade associados ao procedimento reconstrutivo. A enxertia óssea ganhou uma excelente ferramenta com a descoberta das proteínas ósseas morfogenéticas na década de 1960. O benefício da obtenção de matriz óssea verdadeira e funcional, sem a necessidade de um segundo sítio cirúrgico, parece ser a grande vantagem do uso das proteínas ósseas morfogenéticas. Neste contexto, o objetivo deste estudo foi analisar a utilização da rhBMP-2 na regeneração óssea de ameloblastoma mandibular unicístico, detalhando sua estrutura, seus mecanismos de sinalização celular e sua eficácia biológica, além de apresentar potenciais vantagens e desvantagens da utilização clínica das rhBMP-2, enquanto estratégia regenerativa.

Density and migration of mast cells in lip squamous cell carcinoma and actinic cheilitis.

Mast cells (MCs) display a diversity of roles that may contribute to the stromal microenvironment alterations during tumor progression. The aim of this study was to investigate MC populations expressing tryptase and c-kit in lip squamous cell carcinoma (lip SCC) (n=37), actinic cheilitis (AC) (n=15) and normal lip mucosa (control) (n=6), as well as their relationship with microscopic parameters (collagen degeneration, elastin changes, angiogenesis and proliferative index). Tryptase, c-kit, CD31 and Ki-67 expressions were analyzed by means of immunohistochemistry and collagen and elastic fibers were visualized with Picrosirus and Verhoeff's stain, respectively. The numbers of tryptase+ MC were significantly higher in lip SCC when compared with control (P=0.01), while a similar density of these cells was observed in AC and lip SCC (P=0.09). The density of c-kit+ MC was similar in all groups examined (P=0.65). MC migration (c-kit+/Tryptase+ relationship) was 69% in lip SCC, 60% in AC and 100% in control. The number of CD31+ blood vessels was significantly higher in the lip SCC when compared with control and AC (P<0.01). The increase of MCs and angiogenesis in lip SCC may reflect an important modification in the tumor microenvironment during squamous photo-carcinogenesis.